1. Field of the Invention
The present invention relates to a film antenna and an electronic equipment.
2. Description of Related Art
Antennas for wireless communication have been hitherto miniaturized in mobile terminals having a wireless communication function such as handy terminal, PDA (Personal Digital Assistant), etc. Dipole antennas having a large resonance band (broad band) have been considered as antennas for wireless communication in mobile terminals.
An antenna having paired planar isosceles triangle elements which are designed like the shape of wings of a butterfly has been considered (see Patent Document 1: JP-A-2007-27906, for example). That is, the area of the element is increased to obtain a broad band.
Furthermore, as the dipole antenna of the broad band, an antenna having paired short-rod-shaped antenna element and long-rod-shaped antenna element has been considered (for example, see Patent Document 2: JP-A-2007-43594). That is, the antenna has the two rod-shaped elements having different resonance frequencies, which are paired.
However, in the conventional dipole antenna equipped with the elements having the butterfly-wing shape, the length in the vertical direction of each element is increased, and it is difficult to miniaturize the dipole antenna and equipment having the dipole antenna mounted therein.
Furthermore, in the dipole antenna having two paired rod-shaped elements, the impedance thereof is larger than 50[Ω]. Therefore, a balun is required for impedance matching. The balun is an impedance matching device. Accordingly, an area for forming the balun is required, and thus it is difficult to miniaturize the dipole antenna and equipment having the dipole antenna mounted therein.